Channel estimation in OFDM systems operating under high mobility using Wiener filter combined basis expansion model

In this article, we first thoroughly analyze Wiener filter combined least squares based channel estimation (WF-LS) and then illustrate its limitation in high-speed mobile environments. Based on the analysis, we propose to combine WF with basis expansion model (BEM) based channel estimation to deal with channel estimation in various mobile environments, especially in high-speed cases. The expression for Wiener filter combined BEM based channel estimation (WF-BEM) is derived and the result explicitly considers the effect of intercarrier interference (ICI) that occurs in orthogonal frequency division multiplexing (OFDM) systems when operating under high mobility. The simulation results demonstrate that our proposed WF-BEM is better than WF-LS in time-varying channels, and the performance improvement is significant especially in fast time-varying channels.